Bobthebirder's Video Blog

Rodwell Trail
Tuesday August 28th 2012

Not far from my house is the old railway line that used to take passengers and freight between Weymouth and Portland.
Disused since the early 1960's it is now a very popular pedestrian and cycle route, with many overgrown areas that support plenty of wildlife.
One of my favourite spots is the Downclose Cutting where I used to catch lizards as a child, just after the line had closed.
Walking through there today my eye was caught by this very bright female Common Blue butterfly resting on a flower of Creeping Thistle.

Many books show this butterfly as having a brown female, but in fact the blue form is far more common, at least in this area.
It was only when I looked at this video back home on my computer that I realised how clearly you could see the butterfly's proboscis as it searched the flower for any florets that still held a drop of nectar.
Look closely at this next section and you'll see how it is able to bend independently at the tip so that it can enter the tiny opening at the mouth of each individual floret on the thistle flower.

After about five minutes of waiting for the butterfly to open its wings again I was thinking about walking on and looking for something else to film when I noticed something was crawling up the other flower next to the butterfly.
It was a real stroke of luck that a) I hadn't already walked on and b) the other flower was in the same field of focus as the one with the butterfly on, as what you are about to see is normally very difficult to film.
But first a warning: if you are a serious arachnophobe you might want to skip this bit!

At this point I was convinced that the Harvestman was about to kill and eat the butterfly.
Harvestmen are closely related to spiders, but do not bite or make webs.
Their food is pretty well anything they can chew up in their tiny mouths, and they can often catch other insects although I've never seen one eat anything as large as butterfly before.
There are many different species in the UK, none of which have English names and none of which I would recognise, so I posted a photo onto iSpot to see if it could be identified by one of their experts.
Within 24 hours one such expert (who I happen to know lives in Dorset) had identified it as Leiobunum rotundum, see http://www.ispot.org.uk/node/290686.

Here's the denouement of this potentially fatal encounter - not what I expected!